Automobile mats used for covering the flooring of an automobile are typically molded laminated products, and often are composed of a tufted carpet which has a felt or heavy jute padding laminated to the back surface thereof by the use of a hot-melt thermoplastic adhesive. Automobile mats so prepared are heated and molded prior to use to form a molded automobile mat of a molded stiff form, for example, wherein the mat will fit over the transmission hump on the floor of the automobile, and which mat has open areas cut for the accelerator and brake pedals, so that the molded laminated automobile mat may be easily inserted onto the floor of an automobile.
Automobile mats prepared with the use of felt and heavy jute padding as a backing are not wholly satisfactory since both felt and jute are often imported, and the deliveries and qualities of these materials suffer wide variations. In addition, felt and jute tend to absorb water, and further, felt paddings are difficult to be molded, so that they often must be precut prior to the laminating step.
A typical process for the preparation of a tufted carpet automobile carpet mat would comprise the sprinkling of a relatively uniform coating of a hot-melt adhesive material, such as polyethylene or a modified polyethylene material in flake or pellet form, onto the back surface of a roll of tufted carpet. The coated carpet is then introduced into and sent through an oven or under infrared heaters and the hot-melt material melted for a time to coat the back surface of the carpet. The carpet and hot-melt adhesive are then cooled, cut to size and stacked. The hot-melt adhesive serves as a means to anchlor the tufts of the carpet where the face surface of the automobile mat has a tufted carpet, and in addition serves later to laminate a precut felt pad to the back surface of the carpet. At room temperature of 60.degree. to 80.degree. F. or slightly above, e.g., up to about 100.degree. F., the hot-melt adhesive imparts a stiff form to the automobile mat. When an automobile mat is to be prepared, precut felt padding material is placed into a mold, the hot-melt surface on the coated carpet is then heated up to soften the surface, such as by the use of a hot-air oven or by radiant infrared heaters, and then placed into the mold. The mold, while the hot-melt adhesive is temperature-moldable, forms the carpet and padding to the desired shape. Where the carpet is sufficiently pliable by preheating, the carpet may be cold-molded and then the molded automobile mat removed and stored, nested together ready for shipment or use.
It is desirable to prepare automobile mats without the use of felt or jute padding, and without the use of pre-cutting of such padding, and to prepare such mats on a production basis. In addition, it would be most advantageous to prepare an automobile mat with better cushioning and sound-deadening and bulk and mobility characteristics than the prior-art automobile mats.
U.S. Pat. No. 4,016,318 describes use of polyurethane for making these mats and furnishes a drawing of typical coating, slitting, heating and cold molding the mat.